Tie bar



June 3, 1941.

J. W. lSETT TIE BAR Filed March 6, 1939 s Sheets-Sheet 1;

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TIE BAR Filed March a, 1939 3 Sheets-Sheet 2 lli Tinv bi WWW/ 7 "-2 \1 mm. l

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BY g g I v June '3, 1941. J. w. ISETT 2,244,337

- TIE BAR Filed March 6, 1939 3 Sheets-Sheet 3 Jo/zzz Warren a and during the pouring process.

Patented June 3, 1941 rrso STATES PATENT ()FFICEQ TIE BAR John Warren Isett, Hinsdale, Ill. Application March 6, 1939, Serial No. 259,939

6 Claims.

This invention relates to concrete construction and is more particularly concerned with a reinforcing or load transfer unit suitable for use in various types of concrete construction, including particularly the building, repairing, or widening of concrete roads and with a method of positioning the same.

In many types of concrete construction, such as, for example, road building, the concrete is poured inslabs which bear a certain space relationship to each other, and it is essential that this relationship be not altered by road use or by the effects of weather. Existing practice has overcome the displacement of the concrete slabs relative to each other by means of steel bars some three feet in length which are embedded in "the concrete at the time of pouring and join the slabs of concrete at the joint.

In order to appreciate the importance of my invention, a more detailed description ofthe construction of. roads employing tie bars/is desirable. Generally speaking, concrete highways are laid in slabs ten feet wide and thirty feet long. In the case of a two-lane highway, two slabs ten feet wide are laid side by side. Longitudinally between the slabs, there may be a joint plate used primarily to form the form wall of the first lane laid during the pouring process. a This longitudinal joint in cross section is frequently of the tongue and groove variety in order to assistin distributing load from one slab to an adjacent slab and to maintain horizontal alignment at the joint.

Of recent years, it has become general practice for all types of joints, whether "straight, concave-convex, or tongue and groove, toplace at right angles to the joint, two or three feet apart, anchor or tie bars embedded in the concrete. These joints are tight in order to prevent penetration of. water.

My invention relates to improved tiebars' and to the simplification of their positioning prior to According to prevailing practice, tie bars arep'o'sitioned by inserting the tie bars into holes in the joint plate and securing the tie "bars in right-angled relationship to the joint plate by wiring them to chairs "or stakes driven into the'sub grade at the extremities of the bars. It is necessary to Wire the tie bars to the chairs or stakes, and this wiring must be secure in order to prevent the impact of the concrete dropped by the mixing machine from clisaligning the bar. This method of mounting the tie bars in the longitudinal joint requires the services of skilled labor. The job is .tuationsi and its other end is r 7 metal cap. This cap is embedded in the concrete,

greased endand the slip bar is free 7 bar.

Perhaps .inost of the difiiculty attributable to the chairs results from the method of spreading the concrete. The bucket of the mixing machine drop-sits load on the sub-grade and the Spreaders commence to push out the pile. They do not lift the concrete but push it. When the concrete reaches the chairs, it is not lifted around the chairs up against the joint plate but pushed there and the chairs receive considerable pressure. Where the tie bar, as in my invention, is positioned without the use of chairs, spreading of the concrete over the lower half of the road does not afiect the tie bars at all. When the concrete rises to the tie bar, it supports and steadies the tie bar as the remaining concrete is pushed into position. p

For the transverse expansion joints, slip bars are used in place of tie bars. The slip bar differs from the tie bar in its function: the tie bar holds the joint tight whereas the slip bar permits the joint to widen or narrow as the. concrete expands or contracts under temperature fluc- The slip bar is anchored in one slab greased and inserted in a as is the to move axially. Dueto the fact that the expansion joint is broader in cross section than the longitudinal joint plate, the slip bar receives greater horizontal positioning than is provided by the longitudinal joint plate. But like the tie bars, the slip bars are positioned by being wired to stakes or chairs in the sub-grade. The transverse expansion joint may consist of twosteel walls spaced by spreader means topped by water impervious material or of cork or some bituminous material.

The principal object of this invention is to provide a tie bar and slip bar which may be tightly afiixed to an expansion joint or joint plate at a desired angle with suli'icient tightness .to withstand the disaligning effect of the spreading concrete. By this structure, it will no longer be necessary to drive the positioning chairs or stakes in the road bed, nor to wire to such chairs and stakes the tie bars or slip bars.-

It is an incidental object or resultof this invention that the life of the tie bars and slip bars will be materially increased. It has been found that the chairs or stakes corrode and disintegrate and thereby form a passage for the destructive forces of nature to reach the tie bar. These tie bars frequently have hooks or prongs at their ends which provide the principal gripping action on the concrete, and tie bars have been found embedded in concrete with the hook or anchor broken from the shank due to the effects of rust and corrosion, coupled with strain. My invention completely sheaths the tie bar in the concrete and thereby eliminates a serious wear factor.

The second object of my invention is to provide a bar of a structure which may be used with equal success as a tie bar or a slip bar. It is general practice today to utilize tie bars for the longitudinal joint and slip bars for the transverse joint, which slows up the work.

A third object of the present invention is to obviate the necessity of increasing the thickness of the concrete sections at or near the inner edges of adjacent sections, which is an expensive and arduous type of construction. By employing a tie bar a substantial portion of the wheel load is transmitted by the bars from section to Figure 10 is a sectional view of a concrete highway or concrete construction showing another form of my slip bar in a transverse expansion joint.

Figure 11 is a view of the form of slip bar of Figure 9 prior to threading into a transverse expansion joint, and

Figure 12 is a view of the slip bar mounted in a metal transverse expansion joint.

As shown in the drawings, [0 and I2 are adjacently disposed slabs of concrete, as in a highway, separated by a joint plate l4. Joint plate l4 may be made of steel, in which case it constitutes the side wall of the form during the pouring process, or it may be made of cork or some bituminous composition in strip form inserted on the concrete side adjacent to a temporary form thereafter to be removed. In some instances, the cork or bituminous spacer strip is of sufficient structural strength to perform the form duties of a steel joint plate during the pouring process.

section, thereby making the thickened inner edges of adjacent sections unnecessary.

A further object of the present invention is to make unnecessary the increasing of the thickness of the concrete at or near the inner edges of adjacent sections in multiple lane roads poured at the same time in which the proximate edges of adjacent sections are provided with conventional tongue and groove construction. By the employment of my improved units, the complemental concave and convex sections are securely.

tied together and will not separate through the contraction or expansion of the concrete or from any other cause.

Another object is to eliminate the necessity of tying transverse edge bars and reinforcing mesh to the tie bars and slip bars. In accordance with one practice of my invention a hook may be formed on an extremity of each tie or slip bar and the edge bars and mesh may be simply laid into the hook thereby securely fas-.

tening them to the tie or slip bars without the necessity of either tying or wiring them in position.

Other objects of the invention will become apparent from reading the following specification in the light of the accompanying drawings, comprising three sheets, in which:

Figure l is a sectional view of a concrete highway or concrete construction having one of my improved tie bars embedded therein.

Figure 2 is a view similar to Figure 1 showing a somewhat modified form of tie bar in mesh with reinforcing rods.

Figure 3 is a figure similar to Figures 1 and 2 showing a straight rod and a washer disposed at the point of engagement betweenthe center joint plate and the tie bar.

Figure 4 is a view similar to Figures 1 and 2 of a further modification of the invention.

Figure 5 shows a plurality of slip bars mounted in accordance with the present invention and provided with caps which permit lengthwise slipping.

Figure 6 is a view similar to Figure 5 showing the use of reinforcing members in connection with the slip bars and slip caps.

Figure '7 illustrates the straight-ended slip bars of Figure 3 provided with slip caps.

Figures 8 and 9 illustrate alternative methods of securing the tie bar in position with respect to the center joint plate.

sin

The numeral l6 identifies a tie bar having ends l8 and 20, which may be straight, as shown in Figure 3, or bent at right angles to the axis of the shank of tie bar I6, as shown in Figure 1, or bent into U-shaped gripping means, as shown in Figure 2. The tie bar 16 is centrally threaded at 22. In Figures 1 through 4, the tie bar [8 is permanently located in a pre-determined position in relation to strip 14 by means of nuts 24 riding threads 22 of tie bar I6. By tightening the nuts 24 against the joint plate 14, a rightangled relationship may be maintained. The width and thickness of the nuts 24 may be varied to meet the particular conditions of strain that are encountered on certain types of concrete pouring and to meet varying tensile and structural strength of the strip H.

In Figure 9, I present a unique substitute for the nut 24. I4 is the joint plate, 44 the tie bar, and 4 0 a U-shaped clip having arms 46 and 48 separated by a distance less than the diameter of tie bar I6 leaving hole 42. When the tie bar has been inserted in the joint plate l4 and centrally positioned, the clip 40 is rested above the threads 22 and driven down with a sharp blow of a hammer. A second clip is similarly clamped into the threads of the other side of the joint plate H.

In addition to the use of nuts and clips, there may be seen in Figure 8 a cross section of a suggested collar 36, which may be fastened to the tie bar l6 by some special tool or may be welded thereto.

In the case of the longitudinal joints between the parallel strips of concrete slab and for the contraction joints lying transverse of a highway, the method of assembling is as follows. The joint plate is erected in the grade. It carries a series of spaced holes such as 42 and into these are centrally positioned the tie bars. The joint plate l4 may be tongue and groove, convex-concave, or straight in cross section. The problem is to fix the tie bars at right angles to the joint plate l4 without the use of chairs or stakes. As explained above, this is accomplished by using a flat nut or clip plate or collar, in conjunction with the threaded shank, which obtains a substantial purchase on a wall of the joint plate H. When two are brought up against opposite sides of the joint plate 14, the tie bar is held in fixed position. In the case of the form shown in Figure 2, it is necessary to shape one end, [8 or 20, into the U form on the job, because other- 2,244,337 Wise they cannot be inserted through the hole in the joint plate '52 and 54, spread apart by arcuate or angular pieces of metal 56 and '58 which permit contraction of the joint. It can readily be seen that my form of invention used in Figures 1 through 4 will be readily adaptable to the thicker expansion joints and equally effective to accomplish the purpose.

A second adaptation of my invention may be seen in Figures through 12. In this "adaptation, one end of the bar 60 isstraight, while the other end 64 carries a hookfor firrn' anchorage in the concrete. The threads -66 are raised above the surface of the shank of the bar 60, in order that the nut 68 may be slipped over the end and threaded to a position shown and for the threading purpose about to be disclosed. The expansion joint 10 may be of cork or some bituminous composition having considerable structural strength yet capable of compression, and is perforated by a hole 12 which will pass the end 62 of the bar 60. In using, the bar 60 is inserted through the hole 10, as may be seen in Figure 11 and the threads 66 turn internal threads into the expansion joint 19 until the nut 68 firmly engages the wall of expansion joint 10. In some cases, it may be desirable to further tighten the bar by lengthening the threads and afiixing a nut on the other side, in much the same fashion as described in the first form of this invention.

Generally speaking, the method of erecting concrete road forms under this form of my invention is to position the joint plate, whether it be a contraction or expansion joint, perforate the plates by holes which will pass the shank of my bar and then by means of raised threads on the tie bar form internal threads in the spacer strip itself, drawing up a nut or collar against the surface of the plate to lock the tie bar in firm right-angled relationship to the strip.

This same construction of tie bar and this same method of erecting concrete forms may be pursued for steel expansion joints such as 59 in Figure 12. The holes in the transverse expansion joints are cut to a size which will pass the unthreaded shank at the end 62 of the tie bar 60, and the threads 65 are sufiiciently hard to enable them to work a suitable thread into the steel walls 52 and 54.

A modification of my invention which may be adapted to the first form where the joint is to be held tight is shown in Figure 3. The penetration of water down the strip l4 increases with use, and in addition to its destruction of the highway by expansion when frozen, it rusts the tie bar at the joint between the two concrete slabs. The numeral represents a rubber double collar having a hole which will pass the tie bar l6 and which may be fitted into an enlarged hole in the strip I 4. It is obvious that once mounted, the tie bar is completely embedded in either rubber or concrete. Water cannot reach it.

It is apparent that any one of my tie bars may be adapted to the slip bar function by simply having one end The-caps 32 are placed slip bars the tie bar B0 of" Figure tutes of wiring the slip rods to the stakes or chairs straight, greasing this end, and-addinga cap.

In Figures -5' through 7 "are shown an arrangement of my slip bars, which facilitates roadco'nstruction. In Figure 5, I employ-as aslip'bar a tie bar having a right angle hook at 'one'en d. over the open end and with a highly greased surface of the-straight end of the bar, the'bar will slip in and ou't of the concrete slab during expansion and contraction.

of concrete, which permits free longitudinal movement of the slabs during expansion omentraction and yet distributes'any load on one slab to the adjacent slab. j

In Figure 6, I havealt'e'rnately imsge as 34 are insertedin to the hooks of the slip 60 and wiring is unnecessary' This constia great labor saving over present practice bars bars together with any other mesh reinforcing material. While I have shown in Figures 5 through 7 the use of this alternate arrangement of single hook bars for transverse contraction joints, it is apparent that the also called here to 66 on the bars into the tie bar ber to maintain the latter and the bar in assembled relationship, said engaging means being adapted to lock on the threaded shank of the tie bar.

2. A reinforcing assemblage struction comprising,

for concrete conin combination, a vertically her to maintain the latter and the bar in assembled relationship, said engaging means comprising U-shaped clips adapted to lock on the threads of the shank of the tie bar.

3. A reinforcing assemblage for concrete construction comprising, in combination, a vertical- 1y extending elongated member adapted to be disposed between the adjacent sections of concrete, and a tie bar having a threaded shank and associated in threaded engagement with said member, and a collar on the threaded shank flush with one face of said member.

4. A reinforcing assemblage for concrete construction comprising, in combination, a vertically extended elongated member adapted to be disposed between the adjacent sections of concrete, and a tie bar having a threaded shank and associated in threaded engagement with said member, and a nut on said threaded shank drawn tightly against one face of said vertically extended elongated member.

5. A reinforcing assemblage for concrete construction comprising, in combination, a vertically extending elongated member adapted to be disposed between adjacent sections of concrete and a tie bar having a threaded shank associated with said member, said bar being provided with means for engaging opposite sides of the elongated member to maintain the latter and the bar in assembled relationship, said engaging means comprising nuts adapted to be drawn up on the threads against the opposite sides of the elongated member.

6. A reinforcing assemblage for concrete construction comprising, in combination, a vertical- 1y extending elongated member adapted to be disposed between the adjacent sections of concrete and a tie bar having a threaded shank associated with said member, said bar being provided with means adapted to lock on the threaded shank of the tie bar and engaging opposite sides of the elongated member to maintain the latter and the bar in assembled relationship, there being a corrosion resisting member intermediate the engaging means and the sides of the elongated member.

JOHN WARREN ISETT. 

